Angle (Right angle and Vertical line, Acute angle and Obtuse angle)：練習問題

Which of the following describes an angle that is exactly like the corner of a square?

Look at the corner of your textbook. What type of angle is formed at the corner?

If you take a square piece of paper and fold it exactly in half from one corner to the opposite corner, and then fold it in half again in the same direction, what kind of angle is formed at the folded corner?

An angle measures more than \(90^\circ\) but less than \(180^\circ\). What type of angle is it?

Imagine a clock. If the minute hand is pointing exactly at the number 12 (a vertical line), and then moves to point at the number 5, what type of angle has it moved through?

What kind of angle measures less than $$90^\text{o}$$?

Imagine a square piece of paper. If you draw a line from one corner that perfectly divides the corner angle into two equal parts, what type of angle does each of these new, smaller angles represent?

Two lines, AB and CD, intersect at point O. Line AB is a horizontal line, and line CD is a vertical line. What type of angle is \(\angle AOC\)? Now, if a new line, OE, is drawn from O such that \(\angle COE\) is an acute angle and the combined angle \(\angle AOE\) is greater than a right angle but less than a straight line, what type of angle is \(\angle AOE\)?

Imagine a person standing perfectly straight. This person's body forms a vertical line. The ground beneath their feet is a horizontal line.

a) What type of angle is formed between the person's body and the ground?

b) Now, the person bends their arm at the elbow, raising their forearm slightly, so that the angle formed at the elbow is smaller than the angle between their body and the ground. What type of angle is formed at their elbow?

c) The person then stretches their arm out to the side, past the point where it would be straight up, but not completely flat against their back. The angle at their shoulder is now wider than the angle between their body and the ground, but not a straight line. What type of angle is formed at their shoulder?

Look at the following angles formed by lines intersecting at a point P.

Line AB is a horizontal line passing through P.

Line CD is a vertical line passing through P.

a) What is the measure of \(\angle APD\)? What type of angle is it?

b) A new ray, PF, is drawn such that \(\angle APF = 60^ {o}\). Is \(\angle APF\) an acute, right, or obtuse angle?

c) Another ray, PG, is drawn such that \(\angle APG = 135^ {o}\). Is \(\angle APG\) an acute, right, or obtuse angle?

d) Order the angles \(\angle APF\), \(\angle APD\), and \(\angle APG\) from smallest to largest.